Charles e



C. E. BROAD.

WAIER LEVEL lNDlCATOR.

APPLICATION FILED DEC.24.1917.

1 308,620. Patented July 1, 1919.

due COLUMBIA PLANOGRAPH co.. WASHINGTON. n. c.

UNITED STATES PATENT OFFICE.

CHARLES E. BROAD, OF NEWTON, MASSACHUSETTS, ASSIGNOB T0 STANLEY MOTORCARRIAGE COMPANY, OF NEWTON, MASSACHUSETTS, A CORPORATION OF DELA- WARE.

WATER-LEVEL INDICATOR.

Specification of Letters Patent.

Patented J uly 1, 1919.

To all whom it may concern:

Be it known that I, CHARLES E. BROAD, a citizen of the United States,residing at Newton, in the county of Middlesex and State ofMassachusetts, have invented certain Improvements in Water-LevelIndicators, of which the following description, in connection with theaccompanying rawings, is a specification, like reference characters onthe drawings indicating like parts in the several figures.

This invention relates to water level indi eators for boilers and thelike and is particularly concerned with the requirements of devices ofthis character for use on high pressure steam boilers.

As is well understood by those skilled in this art, the bursting of thegage glass or water level indicator of a steam boiler in which a highpressure is arried may have very disastrous results to those in theimmediate vicinity. Various cxpedients have been adopted to reduce thedanger attendin accidents of this characl er and one form 0 indicatingapparatus proposed with this end in View comprises a float arranged torise and fall with changes in the level of the water in the boiler, amagnet connected. with said float to be moved as the float rises andfalls, a casing inclosing these parts, and a needle outside the casingbut within the field of force of the magnet so that it follows themovements of the magnet and thus indicates the changes in the waterlevel. Indicating devices of this character are well adapted towithstand high pressures, and while they have been used to a onsiderableextent on water tanks, gasolene tanks and the like. and to some extenton boilers in. which a relatively low pressure is maintained, they havenever proved successful, so far as I have been able to learn, on highpressure boilers due to the fact that the high temperatures necessarilymaintained in these high pressure installations de-magnetize the mapnetsand thus render the indicator total y ino erative.

he present invention aims to devise an indicating apparatus of thegeneral character justdescribed, which can be successfully used on highpressure boilers and in other places where the li uid under observationis maintained at a igh temperature. The invention also, aims to improvethe me cherries construction at apparatus at this character with a viewparticularly to reducing the friction, siu'iplifying the construction,reducing the liability of inaccuracy or breakage due to corrosion ofparts and generally improving the construction of apparatus of thistype. It is also an object of the invention to improve the constructionof the floats used in such apparatus.

The manner in which it is proposed to accomplish these objects will bereadily understood from the following description of the embodiment ofthe invention at present pre ferred and the novel features will beparticularly pointed out in the appended claims.

Referring now to the accompanying draw- Tigure 1 is a front elevation ofan app arat-us embodying this invention, a part of the casing of theapparatus being broken away to show the interior construction;

Fig. 2 is a cross sectional view taken substantially on the line 2-2,Fig. 1; and

Fig. 3 is a cross sectional view of a modified construction of easingsection.

The apparatus shown comprises a hollow casing or container designed tobe placed in communication with the boiler, or other device with whichthe apparatus is used. by means of suitable pipe connections 4 and 6 sothat the water level in the container will rise and fall with thechanges in level in the boiler. This container is provided with a neck 8normally closed by a screw threaded cap 10 which is provided with acentral extension 12 designedto form a bearing for one end of a shaft14. This shaft extends longitudinally through the bore in the extension12 and through a pipe or tube 16, one end of which is threadediuto theca 10 and the other end of which is threade into a member 18. Thismember is constructed to form a bearing for the other end of the shaft14 and also is recessed, as indicated at 20, to form a chamber for a barmagnet 22 which is mounted on the forward end of the shaft 14. The frontof this chamber is closed b a ca 24 threaded on to the member 18.liZounte fast on the opposite end of the shaft 14 is a float 26 that isconnected to the shaft by a stem 28 and is partially counterbalan ed bya weight 30.

Any suitable form of float construction may be employed. I prefer,however, to use a" solid float rather than a hollow float of the typemore commonly uml nines the letter floats are liable to corrode after atime and become leaky, thus either rendering the indicator inaccurate ortotally inoperative. Accordingly, I prefer to "make the float of somematerial, such for instance, as aluminuni, which may be heavier thanwaiterpand then to couul'crbalance this member with some metal, such forinstance, as leadpof greater density than the float and of such a massthat it will cause the float to ride buoyantly on the surface of thewater even if, without such a counterbalance, this float would sink. foris far more reliable than are the floats more commonly used, and itavoids the danger of disturbing the accuracy of the readings of theindicator caused by the leakage of the float or its absorption of water,due to its porosity. It will be understood that the term solid float isused to differentiate the float above described from those which dependfor their buoyancy upon some peculiar shape rather than upon the displacement of water by the solid material of the float. By properlycounterbalancing a float of this character it may be made to ride asbuoyantlyjon the surface of the water as would a hollow float, eventhough the solid float is made of such material that it would sink orsubstantially submerge if it were not counterbalanced. Obviously thecounterbalance could be mounted. if desired, so that it would always beout of water.

It will now be evident as the water level in the container 2 risesandfalls the float 26 will rise and fall and thus turn the shaft 14 aboutits axis. The shaft. of course, transmits this turning motion to the barmagnet The movements of the magnet are followed by a ointer or indicatorpivoted co-axially with the shaft 1% and mounted outside the magnetchamber-but within the field of force of the magnet. This pointer playsover a suitably graduated dial 3st. In the construction shown thepointer is rotatably anounted on a. pin that, projects from the face'ofthe dial plate34. i This dial is cupped or provided with a peripheralupstanding flange on whichrests aglass face plate .36. A! sheet metalring or collar-38 encircles the flange of the dial plate 34 and i hasits edge soldered or otherwise secured to tl'iepe ripheral flange ofa'plate 40 that overlies the face plate 36 and is cut outito afford aview of the part of the dial over which the pointer -moves. cars 44- aresecured to both the members 84 and 38 by rivets {16, Eig. 2,. andscrews-48 extend through these ears and fasten the 'dial and the other-parts secured there-to to the face of the cap-24. The members 18- and24; preferably are. made of brass, bronze or some non-magnetic atenialso'that they do not'short-cirouit thli lines: of force of the magnetBQ.

A construction of this charac- Several :small It is obvious that whenthis apparatus is used on a steam boiler, the steam will force its wayalong the shaft 14 into the magnet chambeWQO and; if the pressurecarried on the boiler is higl'i enough, theheat so transmitted to themagnet will de-magnetizc it, thus rendering the apparatus inoperative.

hnorder to prevent this action il have located the magnet at a pointrelatively remote fromthe container 2 in which the float is mounted, andI have provided the pipe 16 that connects the magnet chamber with thefloat chamber with a sleeve 50 having a series of radiating disks orfins 52 projecting therefrom. This sleeve is brazed or fitted closely onthe pipe 16 so that it is in inti mate contact with it and thus willconduct heat readily to the fins 52 which, in turn, will dissipate it inthe surrounding atmosphere. The pipe is made of such a length that itwill accouunodate the required numbeiwof these radiating fins to preventthe transmission of a suflicieut degree of heat to the magnet todeanagnetize it. This construction maintains a water seal around theshaft 14 at practically all times. The radiating members can readily beproportioned in accordance with the conditions existing intheinstallation with which the apparatus is to be used so that all dangerof demagnetizing the magnet will be eliminatcd.

Fig; 3 shows a construction in which the caplfi, pipe 16 and the members18, 50 and are integral, primed reference numerals being used todesignate the parts corre sponding to those shown in Fig. 2. This entiremember may be cast in one piece and a hole drilled therethrough for theshaft 14.

' Bearing bushings are then inserted in the due to sudden changesintemperature or to any ordinary blow that might break a gage :glass orother fragile. type .of iindicator. Furthermore this construction hasbeen found through actualuse on boilers in which exceptionally high.pressures are cam'iedto overcome completely the: difficulty: heretc foreexperienced with the ole-magnetizing of the magnet. The movingparts oftherapparatus are all of sturdy construction so that there is no dangerof breakage of the parts due to corrosion and they are so arranged thatcorrosion is not liable to interfere with the movements of the parts.

Vhile I have herein shown and described the best embodiment of theinvention of which I am at present aware, it is obvious that theinvention may be embodied in other forms than that shown withoutdeparting from the essential spirit of the invention.

What I claim as new is:

1. A water level indicating apparatus for high pressure boilers having,in combination, a float, a magnet located at a point relatively remotefrom said float, means connecting said float and magnet arranged totransmit motion from the float to the magnet, a casing inclosing saidfloat, magnet and transmission means, and including an elongated portionprovided with heat radiating means serving to prevent the transmissionof a high degree of heat to said magnet, and indicating means arrangedto follow the movements of said ma net through the action thereon of thefield of force of the magnet.

2. A Water level indicating apparatus for high pressure boilers, having,in combination, a float, a magnet, means connecting said float andmagnet and arranged to transmit motion from the float to the magnet, acasing inclosing said float, magnet and transmission means and includingan elongated member between said float and magnet through which saidconnections extend and whereby the magnet is located at a pointrelatively remote from the float, said member being provided with heatradiating means and said casing being constructed to maintain a waterseal between said float and magnet.

3. A Water level indicating apparatus, having, in combination, a float,a magnet, a shaft connecting said float and magnet and arranged totransmit motion from the float to the magnet, a casing inclosing saidfloat, magnet and shaft and having bearings supporting said shaft forrotation about its longitudinal axis, and indicating means arranged tofollow the movements of said magnot through the action thereon of thefield of force of the magnet.

4. A water level indicating apparatus for high pressure boilers, having,in combination, a float, a magnet mounted at a point relatively remotefrom said float, a shaft on which said magnet is mounted arranged to beturned about its axis by the movements of said float, a casing providedwith chambers for said float and magnet and having a connection betweensaid chambers through which said shaft extends, means for radiating theheat from said connection, and indicating means positioned adjacent tobut outside of said magnet chamber and within the field of force of themagnet, whereby it is operative to follow the movements of said magnetthrough the action thereon of the field of force of the magnet.

5. A water level indicating apparatus for high pressure boilers, having,in combination, a float, a magnet mounted at a point relatively remotefrom said float, means connecting said magnet and float and arranged totransmit motion from the float to the magnet, a casing provided withchambers for said float and magnet and inclosing the parts of saidapparatus to which steam is admitted, heat-radiating means between saidfloat and magnet chambers constructed and arranged to prevent thetransmission of a suflicient degree of heat to said magnet tode-magnetize it, and indicating means outside of said magnet chamber butmounted within the field of force of the magnet and arranged to followthe movements of said magnet through the action thereon of the field offorce of the magnet.

6. A water level indicating apparatus for high presure boilers. having,in combination, a float, a magnet, a shaft rotatable about itslongitudinal axis connecting said float and magnet to transmit motionfrom the float to the magnet, a casing inclosing said float and magnetand including an clongated member between said float and mag net andthrough which said shaft extends whereby the magnet is located at apoint relatively remote from the float and the heat that would otherwisebe transmitted from the neighborhood of the float is dissipated beforeit reaches the magnet, and indicating means arranged to follow themovements of said magnet through the action on said means of the fieldof force of the magnet.

In testimony whereof I have signed my name to this specification.

CHARLES E. BROAD.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. 0.

